Road construction apparatus designed to automate and standardize the process of paving new roads are well known in the art. One type of such construction apparatus is known as a slip-form paver, which is generally adapted to form a flowable paving material such as concrete continuously along the ground or other base surface, for example, to form a roadway. Diverse forms of such machines have been described in prior patents, representative examples of which may be found in U.S. Pat. Nos. 3,175,478; 3,264,958; 3,637,026; 3,771,892; 3,970,405; 4,197,032; 4,360,293; 4,925,340; 4,948,292; 5,044,820, 5,590,977 and 6,715,957.
Conventionally, it is commonplace for paving equipment of this type to support the machine frame on a plurality of drivable transport assemblies, such as so-called crawler track assemblies, adapted to facilitate steerable driving of the paving machine over substantially any ground surface along which a roadway or like surface is to be paved. The frame of the machine is equipped with various devices and mechanisms to perform various functions of the paving operation, including typically an auger or other suitable mechanism for distributing the paving material laterally across the front of the machine, followed by a vertically disposed plate or like structural member, commonly referred to as a strike-off plate, positioned with a lower edge thereof at a desired elevation with respect to the ground surface to be paved to control the amount of paving material passing thereunder and thereby to initially form the material generally as a slab of the desired thickness, and then followed by a substantially horizontally disposed undersurface, commonly referred to as a finishing pan or screed, for purposes of leveling and finishing the concrete material.
In basic operation, a continuous supply of concrete or other suitable paving material is deposited in front of the paving machine between its transport assemblies as the machine is driven over the intended path of the pavement surface, with the auger mechanism initially distributing the paving material laterally, after which the lower edge of the plate “strikes off” a rough slab form of a desired thickness of the concrete material which then is more precisely spread, leveled and finished by the vibration devices followed by the finishing pan.
Additionally, the paving machine must contain and shape the flow of concrete as it relates to the side of the roadway. This function is typically handled by a side plate somewhat similar in function to the finishing pan, but disposed perpendicularly at each side of the finishing pan. In machines where adjustments may be made to the height of the roadway, it is desirable to have a side plate that is vertically adjustable with respect to the finishing pan to accommodate different roadway heights, since the principal function of the side plate is to contain the flowing concrete within the vertical profile of the roadway.
This containment function necessitates a tight connection between the side plate and the finishing pan, because of the nature of concrete under vibrational forces. In a typical slip-form paver apparatus, the wet concrete is vibrated to a high degree in order to remove air pockets and to reduce the viscosity of the concrete. Concrete under vibration is highly non-viscous and flows to fill every space within the slip-form apparatus. Consequently, if there is a gap between the finishing pan and the side plate, following the vibration devices, concrete will flow through the gap, potentially exiting the slip-form apparatus. Such a condition is wasteful of time and resources and can damage the paver apparatus through the introduction of concrete into, for instance, the transport assembly.
If the side plate is perfectly perpendicular to the finishing pan, then maintaining a tight connection with the horizontal finishing pan is relatively easy. But in many paving applications, it is desirable to introduce a side batter, or angular offset of the side edges of the finished concrete. When a side batter is introduced in conventional systems, the function of adjusting the height of the side plate necessarily introduces a gap between the side plate and the finishing pan.
Accordingly, there is a need for a side plate system that permits the selection of a side batter while preventing the introduction of gaps in the slip-form area.